Question
It is a disruptive and niche startup with an initial market of 4.5M. Scalable vertically and horizontally. Top category, such as food and technology. But without traction.
Answer
You can value startup based on Net Assets and Expected Profit (Goodwill). Goodwill represents things like brand name, estimated customer base for product and market value of product. You can calculate expected profit by estimating number and size of contracts and opportunities that you think your product will be able to achieve (keeping in view market base and trends).